M ~ Maxim Gunner

M ~ Metals Centre, Mine or Quarry (Ministry of Munitions)

M ~ Miner

M & BCAIF ~ Mining & Boring Company Australian Imperial Force

MAC ~ Motor Ambulance Convoy

MAD ~ Military Accounts Department (India)

MAD ~ Munitions Accounts Department

MALS ~ Motor Airline Section

MAS ~ Motor Airline Section

MAWU ~ Motor Ambulance Workshop Unit

MB ~ Medical Board

MB ~ Mountain battery (India)

MBE ~ Member of the Order of the British Empire

MBO ~ Mineral Burning Oil

MBRGA ~ Mountain Battery Royal Garrison Artillery (India)

MC ~ Military Cross

MC ~ Medical Certificate

MC ~ Mule Corps (India)

MD ~ Mahendra Dhal Regiment (India)

MD ~ Modified Cordite (munitions)

MDS ~ Main Dressing Station

MDS ~ Modified Strip Cordite (munitions)

MDT ~ Modified Tubular Cordite (munitions)

Med ~ Medical

MEA ~ Military Embarkation Authorities

MEC ~ Military Embarkation Commandant

MED ~ Mechanical Engineering Department

MEF ~ Mediterranean Expeditionary Force

MEO ~ Military Embarkation Officer

MFA ~ Mercantile Fleet Auxiliary

MFD ~ Military Forwarding Department

MFD ~ Munitions Finance Department

MFE ~ Manual of Field Engineering

MFE ~ Military Forwarding Establishment

MFO ~ Military Forwarding Officer

MFP ~ Military Foot Police

MG ~ Major-General

MG ~ Metre Gauge (railways)

MG ~ Machine Gun

MGBDAIF ~ Machine Gun Base Depot Australian Imperial Force

MGC ~ Machine Gun Corps

MGC (Cav) ~ Machine Gun Corps Cavalry

MGCRNVR ~ Machine Gun Company Royal Naval Volunteer Reserve

MGGS ~ Major-General General Staff

MGO ~ Major-General of the Ordnance

MGR ~ Machine Gun Regiment

MGRA ~ Major-General Royal Artillery

MGS ~ Machine Gun School

MH ~ Martini-Henry (munitions)

MI ~ Mounted Infantry

MIA ~ Missing in Action

MID ~ Munitions Inventions Department

MIO ~ Department of Inspections of Munitions local office (Ministry of Munitions)

ML ~ Metal Lined (munitions)

MLO ~ Military Landing Officer

MM ~ Ministry of Munitions (Ministry of Munitions)

MM ~ Military Medal

MMC ~ Ministry of Munitions Control

MMG ~ Motor Machine Gun

MMG.Bty ~ Motor Machine Gun Battery

MMGC ~ Motor Machine Gun Corps

MMGS (RA) ~ Motor Machine Gun Service Royal Artillery

MMGS ~ Motor Machine Gun Service (Royal Artillery)

MML ~ Manual of Military Law

MMOP ~ Munitions Mineral Oil Production (Dept)

MMP ~ Military Mounted Police

MMR ~ Mercantile Marine Reserve

MMVCO ~ Middlesex Motor Volunteer Corps of Officers

MO ~ Medical Officer

MOM ~ Ministry of Munitions

MPG ~ Miles per Gallon

MPH ~ Miles per Hour

MPI ~ Mean Point of Impact

MPS ~ Mobile Power Station

MPSC ~ Military Police Staff Corps

MPSC ~ Military Provost Staff Corps

MRU ~ Mobile Repair Unit

MS ~ Munitions Store (Ministry of Munitions)

MS ~ Military Secretary

MSM ~ Meritorious Service Medal

MT ~ Mechanical Transport

MTASC ~ Mechanical Transport Allocation Sub-Committee

MTC ~ Mechanical Transport Committee

MTC ~ Miscellaneous Trades Company (South Africa)

MTD ~ Machine Tool Department

Mtd ~ Mounted

MTM ~ Medium Trench Mortar

MTMBAIF ~ Medium Trench Mortar Battery Australian Imperial Force

MTO ~ Military Telegraph Office

MTCP ~ Mechanical Transport Policy Committee

MTVRP ~ Mechanical Transport Vehicle Reserve Park

MTWTC ~ Mechanical Transport Water Tank Company

MV ~ Muzzle Velocity

MVC ~ Motor Volunteer Corps

MVO ~ Member of the Royal Victorian Order

MVS ~ Mobile Veterinary Section

MWB ~ Munitions Works Board

MWD ~ Mechanical Warfare Department

MWDEA ~ Military Works Department Egyptian Army

MWS ~ Military Works Service (India)

MWSD ~ Mechanical Warfare Supply Department